FOAM LAKE BIRDINGNo. 41 As of this writing we are in the latter half of March – officially spring. All the ponds and waterways around here used to be filled with waterfowl on their wintering grounds, but in the last few days, their numbers have dropped dramatically. A few Blue Winged Teals, Shovelers and Gadwalls are still around, but everything else is heading north – as we will be in less than two weeks! However, another tropical duck has returned to this area of the Rio Grande after wintering still further south. This particular bird is called the Black Bellied Whistling Duck. Older bird books refer to it as a rare visitor, but at present it is very common. In North America it is unique in that it commonly perches in trees, on buildings and power poles. I should mention that Whistling Ducks are not ducks; they just look like ducks. Because Whistling Ducks occur only in the New World, early European pioneers were lost for a name. There was no “ready made” name for them, so they called them “Tree” Ducks. However, only one species, the Black Bellied, actually landed in trees, so ornithologists changed the name to Whistling Ducks because of the strange whistling sound they make (not at all ‘duckie’). Whistling Ducks are more closely related to geese than anything else. When viewed through binoculars, the Black Bellied Whistling Duck is quite striking with its coral red bill, pink legs, black belly, grey head, rich brown body with conspicuous white wing patches. It also has an obvious white eye ring which gives it a strange bug- eyed look. Another characteristic that makes it quite easy to identify, even before its colours are visible, is its habit of standing on one leg. Many other birds do this also, but not to the extent of the Whistling Duck. Unlike “regular” ducks, male and female Black Bellies are identical. Also, unlike “regular” ducks, both parent Black Bellies share in parenting duties. Both characteristics are those of geese and not ducks. This week’s photo shows a pair of Black Bellied Whistling Ducks roosting on a power line. I could not get any good colour detail as it was getting quite dark. I do have good colour photos, but I thought you would enjoy this more. For full colour pictures consult a bird book or my web site. Enjoy. In the meantime, I have to decide what bird to write about next week.